Time asymptotic high order schemes for dissipative BGK hyperbolic systems

We introduce a new class of finite differences schemes to approximate one dimensional dissipative semilinear hyperbolic systems with a BGK structure. Using precise analytical time-decay estimates of the local truncation error, it is possible to design schemes, based on the standard upwind approximation, which are increasingly accurate for large times when approximating small perturbations of constant asymptotic states. Numerical tests show their better performances with respect to those of other schemes.

CFD Maneuvering Prediction of a Twin Screw Vessel with Different Stern Appendages Configuration

The turning circle maneuver of a self-propelled tanker like ship model is numerically simulated through the integration of the unsteady Reynolds averaged Navier-Stokes (uRaNS) equations coupled with the equations of the motion of a rigid body. The solution is achieved by means of the unsteady RANS solver ?navis developed at CNR-INSEAN. The focus here is on the analysis of the maneuvering behavior of the ship with two different stern appendages configurations; namely, a twin screw with a single rudder and a twin screw, twin rudder with a central skeg.

Locally inertial approximations of balance laws arising in (1 + 1)-dimensional general relativity

An elementary model of (1 + 1)-dimensional general relativity, known as "R = T " and mainly developed by Mann and coworkers in the early 1990s, is set up in various contexts. Its formulation, mostly in isothermal coordinates, is derived and a relativistic Euler system of selfgravitating gas coupled to a Liouville equation for the metric's conformal factor is deduced.

A well-balanced scheme able to cope with hydrodynamic limits for linear kinetic models

Well-balanced schemes were introduced to numerically enforce consistency with longtime behavior of the underlying continuous PDE. When applied to linear kinetic models, like the Goldstein-Taylor system, this construction generates discretizations which are inconsistent with the hydrodynamic stiff limit (despite it captures diffusive limits quite well).

METODOLOGIE E APPROCCIO MULTIDISCIPLINARE PER L'ANALISI DEL DEGRADO DEI BENI CULTURALI. I CASI DI STUDIO DI MONTE SANNACE E PALEOPOLIS

The conservation of wall paintings in archaeological sites can be difficult due to the severe damage caused by living organisms, which can degrade substrates as a result of their growth and metabolic activity. The purpose of this study was to provide information on the degradation processes affecting the artefacts of an archaeological site and to predict areas where conservation is most at risk and precarious. The study focussed on the archaeological site of Monte Sannace (Italy) and Paleopolis (Greece).

Gaussian Estimates for the Solutions of Some One-dimensional Stochastic Equations

Using covariance identities based on the Clark-Ocone representation formula we derive Gaussian density bounds and tail estimates for the probability law of the solutions of several types of stochastic differential equations, including Stratonovich equations with boundary condition and irregular drifts, and equations driven by fractional Brownian motion. Our arguments are generally simpler than the existing ones in the literature as our approach avoids the use of the inverse of the Ornstein-Uhlenbeck operator.

Muscl reconstruction and haar wavelets

MUSCL extensions (Monotone Upstream-centered Schemes for Conservation Laws) of the Godunov numerical scheme for scalar conservation laws are shown to admit a rather simple reformulation when recast in the formalism of the Haar multi-resolution analysis of L<sup>2</sup>(R). By pursuing this wavelet reformulation, a seemingly new MUSCL-WB scheme is derived for advection-reaction equations which is stable for a Courant number up to 1 (instead of roughly 1/2 ).

Monte Sannace. Le tombe dipinte dei Peucezi

MONTE SANNACE. Le tombe dipinte dei Peucezi: le indagini su questa collina della provincia di Bari hanno restituito l'esempio meglio conservato di una città della Puglia preromana, ma per capire il livello di civiltà e i rapporti culturali delle genti peucezie che vi si insediarono rivestono particolare importanza le pitture di alcune tombe monumentali appartenute alle élites aristocratiche del luogo.

Rheologic and dynamic behavior of sheared vesicle suspensions

The rheology and dynamics of suspensions of fluid vesicles is investigated by a combination of molecular dynamics and mesoscale hydrodynamics simulations in two dimensions. The vesicle suspension is confined between two no-slip shearing walls. The flow behavior is studied as a function of the shear rate, the volume fraction of vesicles, and the viscosity ratio between inside and outside fluids. Results are obtained for the interactions of two vesicles, the intrinsic viscosity of the suspension, and the cell-free layer near the walls.